Figure 6. Role of conserved leucine residues in N-alpha in EnvZ_per oligomerization.

(A) Helical wheel representation of the predicted N-terminal α-helix of EnvZ_per. Hydrophobic residues are shaded. Arrows indicate the position of alanine substitution mutations. (B) SDS/PAGE analysis of pull-down assays of mutant EnvZ_per. Assays were performed in 20 mM potassium phosphate, pH 8, and 50 mM NaCl. Quantification of the ratio of UT/His₆-tagged protein by densitometry is represented by the histogram. Results are means±S.D.